Calendar



M. E. DONOW May 16, 1950 CALENDAR 4 Sheets-Sheet 1 Filed Aug. 5, 1947 INVENTOR M01713 DOIYOM/ BY Q AT'TORNEY M. E. DONOW May 16, 1950 May 16, B950 DQNOW 2,507,697

CALENDAR Filed Aug. 5, 1947 4 Sheets-Sheet 3 INVENTOR Morris 1500/7014 y 1950 M. E. DONOW 2,507,697

CALENDAR Filed Aug. 5, 1947 4 Sheets-Sheet 4 INVENTOR JV/orrzls fflonon ATTORNEY Patented May 16, 1950 UNITED STATES i T ENT OFFICE CALENDAR Morris E. Donow, New York, N. Y.

Application August 5, 1947,"Serial No.- 766,381

6 Claims. (Cl. 40-115) opening through which can be seen a monthly calendar arranged like the usual monthly calendar.

Another object of this invention to provide a perpetual calendar of the character described which will give monthly calendars on either the Gregorian or Julian systems.

Still a further object of this invention is to a perpetual calendar of the characted described, which shall be easy to manipulate and easy to read, and which shall-be relatively inexpensive to manufacture and practical and efiicient to a high degree in use.

Other objects of this invention will in part be obvious in part hereinafter pointed out.

The invention, accordingly, consists in. the features of construction, combinations of elements, an. 'rangement of parts which will be exemplithe construction hereinafter described, and of which the scope of application will be indicated in the following claims.

In the accompanying drawing, in which is shown various possible illustrative embodiments of this invention,

l is a top plan view of a calendar emthe invention;

. 2 is a top plan view of the rear disc;

Fig. 3 is a top plan view of next to the rear disc; and

Fig. i is a top plan view of the second disc' from the top.

Referring now in detail to the drawing, ill designates a perpetual calendar embodying the invention. The same comprises a top disc ll formed with a center opening through which there extends an eyelet or other pivot pin l2. Also mounted on the pivot pin i2 is a disc 13 next to the disc ii, a third disc l4 and a rear disc 15. The disc 53 is of greater diameter than the disc ii. The disc i i is of greater diameter than the d sc i3 and the disc 15 is of greater diameter than the disc 14.

The discs ii, 53, M, !5 may be made or" paper, carhoard, synthetic plastic, metal, wood, or any other suitable material. All of the discs are circular and may be rotated independently on the axial pivot pin l2. The discs, of course, are all formed with center holes through which the pivot adjacentlines of the lines .20 to 21. entire disc is divided by a total of 56 lines into 56 numeral 28.

.pins I2 pass. The rear disc I E-is divided by equiangularly spaced radial lines 20, 2 I, 22, 23, 24, 25, 29 and'IZi into eight equal sectors 28, 29, 39, 3!,

'32, and 35. The radial lines 29 to Zlpreferably extend to the outer edge of the disc [5. Each of the eight spaces 28 to 35, respectively, are

divided by six equiangularly spaced radial lines 36 into seven equiangular sectors or spacesS'i. Of course, the six-lines 36 are between a pair of Thus, the

spaces. The number of spaces is a multiple of seven.

Referring now to the space 29, to the right of the second line 36 to the right of line 2|, there is marked the numerals 01, 29, 57, 85

arranged radially from the outer end inwardly. The term -to the right means in this specifica- -tion-in.a.c1ockwise direction. On the left side of said'line next to numeral 29, appears the Also on the left side of said line, next to numeral 57 appears numeral 56. Also on the left sideof said line next to numeral 85 appearsthe numeral 84. It will now be understood that on the left side of said line appear numeralswhich'indicate leap years, whereas, on therightsideof the line appear numerals indicating common years. This arrangement is true of all the year numbers as will appear hereinafter.

On the right side of the third line 36, to the right of line2 l, in=space-29appear the numerals 02,

30, 58 and 86 which are in the same circles as numerals 01, 29, 57 and 85 respectively. To the right of the ith line 35, to the right of line 2|, appear the numerals 03, 31, 59 and 8? arranged in the same respective circles. To the left of line- 22, appear the numerals 04, 32, 60 and 88 respectively, arranged on the four concentric circles. On the right side of line 22, appear numerals O5, 33, 61 and 89 arranged on the four respective circles. On the first line tothe right of line 22 in space 39, to the right of said line, appear numerals 06, 34, 62 and 90 arranged on the four circles. To the right of second line 36 to the right crime 22, appear numerals G7, 35, "63 and 91 arranged in the same four respective circles.

' Also in space 3(lto the left of the fifth line 36 to the right of line 22, appear the numerals 08, 36, 64 and 92 arranged in the four concentric circles. To the right of said last mentioned line- 36, appearthe numerals 09, 37, -and 93.on-the' four respective circles. On the right of the first line 36,110 the left of line 23 appear the numerals 10," 38, 66 and 94 on the four respective circles. In space 3| to the right of line 23, appear the numerals 11, "39," 6'7 and 95 on the four respective circles. To the left of the third line 36 to the right of line 23 appear the numerals 12," 40, 68 and 96 of the four respective circles. To the right of said last mentioned line 36 appear numerals 13, 41, 69 and 97 on the four respective circles. To the right of the 4th line 36 to the right of line 23 appear numerals 14, 42, 70" and 98 on the four respective circles. To the right of the 5th line 36 to the right of line 23 appear numerals 15, 43, '71 and 99 on the four concentric circles.

In space 32, to the left of the first line 36 to the right of line 24 appear numerals 16, 44 and '72 on the outer 3 respective circles. Thus, numerals 16, 44" and "72 are in the same circles as numerals "15," 43 and '71, respectively. To the right of said first line 36 to the right of line 24 are numerals 1'7, "45 and '73 on the same circles as numerals 16, 44 and 7 respectively.

To the right of the second line 36 to the right of line 24 are numerals 18, "46 and '74 on the three outer circles respectively. To the right of the third line 36 to the right of line 24 are numerals 19, 4'7 and '75 on the three outer respective circles. On the left of the first line 36 to the left of line 25 are numerals 20, 48 and "'76" on the three outer circles respectively. To the right of said last mentioned line 36 are numerals 21," "49 and '77 on the three outer respective circles. numerals 22, 50" and '78 on the three outer respective circles. To the right of the first line 36 to the right of line 25 are numerals 23, 51" and '79 on the three outer circles respectively.

To the left of the fourth line 36 to the right of line 25 are numerals 24, 52 and 80 on the three outer circles respectively. To the right of said last mentioned line 36 are numerals 25, "53 and "81 on the three outer circles respectively. To the right of the fifth line 36, to the right of line 25 are numerals 26, 54 and "82 on the three outer circles respectively. To the right of the first line 36 to the left of line 26 are numerals 27, 55 and 83 on the three outer circles respectively.

In space 34 to the left of the first line 36 to the right of line 26 appear radially marked @2060. The G is on the outermost circle, that is, on the same circle as the numeral 27. To the right of said first line 36 to the right of line 26 also arranged radially from the outer end inwardly, is the notation G1900 aligned with the notation "(32000." To the right of the third line 36 to the right of line 26 appears the notation G1800 similarly arranged. To the right of the fifth line 36 to the right of line 26 appears the notation "G2100 similarly arranged. The G's" in space 34 indicate Gregorian calendar system as will appear hereinafter.

In space 35 on the left of the first space 36 to the right of line 27 radially arranged from the outer end inwardly appears the notion Jl900," arranged similar to (32100. To the left of the second line 36 to the right of line 27 appears the notation J1800 similarly arranged. To the left of the third line 36 to the right of line 27 appears the notation J1'700. To the left of the fourth line 36 to the right of line 27 appears the notation J 1600. To the left of the 5th line 36 to the right of line 27 appears the notation To the right of line 25 are :3.

4 Jl500. To the left of the sixth line 36 to the right of line 27 appears the notation J2100 similarly arranged. To the left of line 20 appears the notation JZOOO, similarly arranged. The J in space 35 indicates Julian calendar system.

The lines and numerals may, of course, be printed, engraved or embossed or otherwise marked in any suitable manner on the disc [5.

The disc 74 overlies the disc l5 and is of somewhat smaller diameter so that an outer circular portion of disc 75 is exposed. In said exposed portion of the back disc I5 can be seen the outer ends of lines 26 to 27, respectively. The disc [4 is divided by eight equiangular spaced radial lines 40 to 47 respectively into eight equiangular spaces 48 to 55 respectively. Each of the spaces 48 to 55 is divided by six equiangularly spaced lines 56 into seven equiangularly spaces 57. Thus, the disc I4 is likewise divided into fiftysix equiangular spaces 57.

The disc [4 is formed with a radial window opening 66 located between the 1st and 2nd lines 56 to the right of line 41. The radial position of opening 65 is such that it would uncover marking JZOOO. It would also uncover numbers on disc [5 located on the four respective circles aforementioned. Adjacent the inner edge of window opening 66 appears the notation Apr." Between the fifth and sixth lines 57 to the right of line 42 is a radial opening 6| located similarly, with respect to the center of the disc, as window opening 66. At the inner end of the opening 67 is the notation Feb L meaning February leap year. Between the fourth and fifth lines 56 to the right of line 44 is a Window opening 62 similarly spaced radially, to window opening 6|. At the inner end of window opening 62 is the notation Feb 0 meaning February common year (not a leap year).

Between the second and third lines 56, to the right of line 46 is a window opening 63, similarly spaced to window openings 60, BI and 62 with respect to the center of the disc. At the inner end of window opening 63 is the notation Dec. Between the third line 56 to the left of line 47 and the second line 56 to the right of said line 47, is a window opening 64. The window opening 64 has an angular extent equivalent to five spaces 57. Its radial position relative to the center of the disc is the same as the opening 53. At the inner edge of opening 64 and between the third and second lines 56 to the left of line 47 is the notation Mar. Also at the inner edge of the window opening 64, between the line 47 and the first and second lines 56 to the left of line 47 is the notation Aug. Between the first line 56 to the left of line 47 and at the inner edge of window 64 is the notation May. Between said line 47 and the first line 56 to the right of said line 47 and at the inner edge of the window opening 64 is the notation Oct. and also Ja-C. The notation "Ja-C means January, common. Between the first and second lines 56 to the right of line 47 and at the inner edge of said window opening 64 is the notation July and also Ja-L, the latter meaning January, leap year.

Disc I4 is also formed with a window opening 65 located between the second line 56 to the right of line 40 and the second line 56 to the left of line 4|. Window opening 65 thus has an angular extent equivalent to three spaces 57. Its radial position is similar to opening 60. At the inner edge of window opening 65, and between the second and third lines 56 to the right of line 40, 1s

spirally arranged numbers.

pears numeral 2.

number 28.

numbers started-there also goes to 28.

ever, number 8-of the first set appears below number 1 of the second set. The set of numbers beginning at line 42. goesto 31.

5 the notation Sept. Between the third and :fourth lines 56 to the right of line 40 and at the inner edge of window 55 is the notation Jun for June. Between the fourth and fifth lines .56 .to the right of line All, and the inner edge of window Opening '65 is the notation Nov.

It will be noted that the outer peripheral portion 68 of disc l4 may be .seen beyond disc [3. On said exposed peripheral portion and in alignment with window 60 is marked the notation Apr. which is, of course, radially aligned with the first mentioned notation "Apr. .Said peripheral portion 68 is also marked with the notations Feb-1, "Feb-c, Dec, Mar., Aug, nMay, n th:: Jars, July, :rJa 1,n (Sept-,4! June and Nov, in radial alignment with the corresponding notations on disc l4.

Thedisc hi is also marked with eight sets of Each set of numbers begins at one of the lines 46 to d! and extends therefrom spirally inwardly in a clockwise direction. Each set of spirally arranged numbers nests within the next sets of numbers. Theeight sets of numbers referred .to are on the portion of thedisc inwardly of the windows 68 to E5. Thus, beginning with line 48, it will be notedthat to the right of said line, appears numher 1 in space .57. Inthe next space, ap-

The numbers are arranged successively.andspirally inwardly and extend to Also, to the right of line ,4! appears the number .1 radially positioned similar to the first mentioned numeral, and the set of How- The Set ofnumbers beginning atline 43 also goes to 31. The set of numbers beginning atAA goes to 30. The set of numbers beginning atl5 goes to 30. Theset of numbers beginning at .46 goes to 29.

The set of numbers beginning at .47 goes to 29.

It will now be'understood that in each space "51, is a column of numbers arranged radially and each numberis seven greater than the next outer number in said column. Thus, the column of numbers in the space 5'! to the right of line 40 In the next column-to the right, the "numbers of 2, 9, 16,

- 23, 30, like in an ordinary monthly calendar.

Referring now to disc l3 which overlies disc M, the same isformed with a radial window opening it having an outer edge El which has the same radius asthe outer edge of the window openings'fiii to'65. "The angular width of window openingl'li is the same as the angular extent of one of the spaces'i51 of disc [4 or a space 3'! of disc E5. The side edges '12 of window ill are radial. 'Theinner edge 73 of window "ID has a radius of curvature which wouldlocate it between the notations of the months at the inner edges of the window openings 6!! to $5 of disc l4 and the spirally arranged numbers on said disc. Thus, when window opening 19 registers with window opening 60, the entire window opening 60 and the notation Apr.,at the inner edgethereof would be seen therethrough.

Thedisc l3,-is formed withanother arcuate ewindow opening 15 having. an outer arcuate edge 15 of a radius of curvature which would locate 1 it just beyond the spirally arranged numbers on disc M. It has an inner arcuate edge I! having a radius of. curvature which wouldlooate it just inside of theaspirally arrangednumbers on disc 14. Sam wind o en 1 ha ra ide eq es is. The an ula xtent of WiPQQW enemas l is equivalent to thirteen spaces 31 or @1. Thus, hr h th W nd w open n 71 ll b exposed thirteen radial spaces 51 on disc if} all the spirally arranged numbers in columns in those thirteen spaces.

overlying the disclfi, isthe top disc l l. Said top disc II is formed with a windowopening 8}] having an outer arcuate edge 8 of the same radius of curvature as the outer edge ll of the window opening is in disc 13. It has an inner arcuate edge 82 having the same radius of curvature as the inner edge .13 of said window opening. It has radial side edges 83, and the angular extent of the windowopening is equivalent to seven spaces 31 or 51.

Said disc I i is furthermore formed witha window opening 90 having outer and inner arcuate 20; 19, 18 arranged successively and spaced apartby the width of one of thespaces 51. Thus, numerals-l8- are aligned with edges 83 as shown in the drawing. Disc His furthermore formed ad.- jacent its outer edge 'withthe following numbers successively arranged, 19, 18, 21, 20;

Numeral aligned with the left edge (as. Numeral is aligned with numeral "16 d- ,jacent edge-8i. Thus, the spaces between numerals-19 and '18? are equivalent to two, spaces 51. Numeral 213' adjacent the outer edge of the disc I l is aligned withnumeral 21 adjacent edge 8|. Numeral 20 adjacent the outer edge of the disc is aligned withnumeral 19 adjacent edge 8|.

The disc may be furthermoremarked adjacent the outer edge thereof with the notation cycle 400 years, Gregorian. Said disc may also be .marked adjacent its outer edge with the following notice Gregorian,since October 15,1582. The disc may also be marked on the same circle as ((18,), (17,, fl.6)!) ((15) 21,}! (20, (19! and 18 with the notations cycle 700 years, Julian and Julian, since January 1st, 46 B. C.

The disc H may also be marked with notations,

Sun, Mon, Tue Wed, Thun, Fri.

and Sat, at the strip between the window can always be seen the window 10.

The method of finding the correct monthly calendar for any month on either Gregorian or Julian systems with the improved calendar embodying the invention willncw be described.

,Disc l3is first moved to bring window opening 10in registry with v the desired monthly notation on disc M. This window opening will be made to register either with window openingtil, SLIM or 63 or with some division of window openings 64 or ,65 so; that through the window opening H1 .will beseen the desired month. The disc,

is held in such position that some portionof the window ,openingtll registers with thewindow .edge of window 10. peripheral edge of disc H is then moved in reg- ;istry with line 24 of disc l5. When that is done ,it will be noted that a month calendar will be .seen from Window 90 showing the 1 to be a opening 10. when the proper month is registered with window opening 10, the three discs ll, 13 and I4 may be rotated together until the proper year number on disc [5 is seen through the window 10. Of course, the numbers on disc [5 give the year in the century and do not give the century years except for the years 1800, 1900, 2000 and 2100 on the Gregorian system or the years 1500, 1600, 1700, 1800, 1900, 2000, 2100 on the Julian calendar. If the year selected is a leap year, the radial line on disc l5 to the right of said leap year is registered with the radial edge at the right of window opening 10. If the year selected is a common year, then the radial line to the left of said year is registered with the left :radial edge of the window opening 10.

When the proper alignment has been made, then discs I3, is and i5 are held together and the top disc I l is moved to bring the proper century number in alignment with the nearest of the lines 20 to 20 on disc 15. By the century numbers is, of course, meant Gregorian century numbers on disc I I, adjacent its outer peripheral edge and Julian century numbers on disc I! adjacent edge 8L When the discs are so set, a complete monthly calendar for the month and year selected will be seen through the window opening 90. For centuries other than 18th to 21st, on the Gregorian calendar, the century selected would be one that difiers by four or multiples of four. Thus, if the 24th century on the Gregorian calendar is desired, the 20th century on the disc H is used, the reason being, of course, that the Gregorian calendar repeats itself every 400 years. For the Julian calendar, the same is true, except that the calendar repeats itself every 700 years. For Gregorian years, 1800, 1900, 2000 and 2100, the corresponding years in space 34 of disc l5 are used. Un-

der the Julian system for the years 1500, 1600, i

1700, 1800, 1900, 2000 and 2100, the corresponding year numbers on space 35 are used. Of course, for all other century years, corresponding numbers on spaces 34 and 35 are used. Thus, for a Gregorian year 2400, the G2000 will be used in space 34. Under the Julian calendar for the year 1000 the J1'700 would be used in space 35.

Taking a case in point, let us suppose that it is desired to find the monthly calendar for July, 1947. Disc 13 is moved to bring window in alignment with the portion of window 64 which is marked July. The two discs i4 and I3 are then moved together until the line to the left of numeral 4'7 on disc l5 registers with the left Numeral 19 at the outer Tuesday and the calendar going to 31. For the :month of February care must be taken to select either Feb-L or Feb-C on disc 14. Also for January care must be taken to either select J -L or J-C on disc M.

It will be noted that the window opening on disc is is equivalent to 13 radial spaces. Thus, the century number on disc I! must be aligned either with the line 20 to 21 on the left or the right of the year selected and appearing on disc l5, whichever will show seven full spaces through the window 90.

It will thus be seen that there is provided a device in which the several objects of this invention are achieved, and which is well adapted .to meet the conditions of practical use.

As various possible embodiments might be made of the above invention, and as various changes might be made in the embodiment above set forth, it is to be understood that all matter herein set forth or shown in the accompanying drawing is to be interpreted as illustrative and not in 2. limiting sense.

Having thus described my invention, I claim as new and desire to secure by Letters Patent:

1. A perpetual calendar comprising four discs, means to mount said discs for rotation about a common axis, the rear disc being marked with year numbers, the disc in front of the rear disc being formed with window openings adapted to expose said year numbers, said last mentioned disc being furthermore formed with spirally arranged day-in-month numbers, and with month indication the disc in front of the last mentioned disc being formed with a window opening adapted to register with the window openings in said disc in front of the rear disc and with selected ones of the month indications on the disc in front of the rear disc, and also formed with a window opening adapted to register with the day-inmonth numbers, and a front disc having a window opening adapted to register with the first window opening in the disc in back of the front disc, and also formed with the second window opening adapted to register with the second window opening in said disc in back of the front disc and the days of the week being marked on the front disc in the space between the two window openings of the front disc.

2. A perpetual calendar comprising four discs, means to mount said discs for rotation about a common axis, the rear disc being marked with year numbers, the disc in front of the rear disc being formed with window openings adapted to expose said year numbers, said last mentioned disc being furthermore formed with spirally arranged day-in-month numbers, and with month indications the disc in front of the last mentioned disc being formed with a window opening adapted to register with the window openings in said disc in front of the rear disc and with selected ones of the month indications on the disc in front of the rear disc, and also formed with a window opening adapted to register with the day-inmonth numbers, and a front disc having a window opening adapted to register with the first window opening in the disc in back of the front disc, and also formed with the second window opening adapted to register with the second window opening in said disc in back of the front disc and the days of the week being marked on the front disc in the space between the two window openings of the front disc, the back disc being of greatest diameter, next to the back disc being of smaller diameter, the disc in front of that disc being of still smaller diameter, and the front disc being of still smaller diameter.

3. A perpetual calendar comprising four discs mounted for independent rotation about a common pivotal axis, the front disc being formed with a pair of arcuate radial aligned window openings, the disc behind the front disc being formed with a pair of window openings of different angular extent but positioned radially similar to the two window openings in the front disc, respectively, the disc in front of the rear disc being formed with a plurality of window openings radially positioned similarly to one of the window openings in the front disc, and being marked with spirally arranged sets of day-inmonth numbers. so located that they may be seen through the other window opening of the front disc, and said rear disc being provided with year numbers which may be selectively seen through registering window openings in the first three discs.

4. A perpetual calendar comprising four superimposed discs mounted for independent rotation about a common pivotal axis, the rear disc being divided into a number of equiangular radial spaces comprising a multiple of '7, and bearing numbers designating year in century in various of said spaces, said numbers being arranged in radial columns in said spaces, the disc next to the rear disc being formed with window openings adapted to expose selected columns of numbers on the rear disc, said Window openings being marked to designate a month for each portion of window opening corresponding to a radial space, said disc in front of the rear disc being marked with nesting radially arranged spiral sets of numbers designated day-in-month, the spiral starting point of each set being seven radial spaces away from the starting point of adjacent sets, the disc behind the front disc being formed with a window opening having an angular extent equivalent to one radial space and adapted to register with window openings with the disc in front of the rear disc, said disc behind the front disc being further formed with an arcuate window opening having a radial extent equivalent to 13 radial spaces and adapted to uncover day of month numbers in said sets, the front disc being formed with an arcuate window opening having an angular extent being equivalent to seven radial spaces, and said window opening being positioned radially similarly to the first window openings in the disc behind the front disc, said front disc being formed with a second window opening having an angular extent similar to the angular extent of said first window opening in the front disc, and the radial position of said second window opening in the front disc being such as to expose seven columns of day-in-month numbers in the disc in front of the rear disc.

5. A perpetual calendar comprising four superimposed discs mounted for independent rotation about a common pivotal axis, the rear disc being divided into a number of equiangular radial spaces comprising a multiple of '7, and bearing numbers designating year in century in various of said spaces, said numbers being arranged in radial columns in said spaces, the disc next to the rear disc being formed with window openings adapted to expose selected columns of numbers on the rear disc, said window openings being marked to designate a month for each portion of window opening corresponding to a radial space, said disc in front of the rear disc being marked with nesting spiral radially arranged sets of numbers designated day-in-month, the spiral starting point of each set being seven radial spaces away from the starting point of adjacent sets, the disc behind the front disc being formed with a window opening having an angular extent equivalent to one radial space and adapted to register with window openings with the disc in front of the rear disc, said disc behind the front disc being further formed with an arcuate window opening having a radial extent equivalent to 13 radial spaces and adapted to uncover day in month numbers in said sets, the front disc being formed with an arcuate window opening having an angular extent being equivalent to seven radial spaces, and said window opening being positioned radially similarly to the first window opening in the disc behind the front disc, said front disc being formed with a second window opening having an angular extent similar to the angular extent of said first window opening in the front disc, and the radial position of said second window opening in the front disc being such as to expose seven columns of dayin-month numbers in the disc in front of the rear disc, the rear disc having the greatest diameter, the disc in front of the rear disc having the next smaller diameter, the disc behind the front disc being still smaller in diameter, and the front disc being smallest in diameter.

6. A perpetual calendar comprising four superimposed discs mounted for independent rotation about a common pivotal axis, the rear disc being divided into a number of equiangular radial spaces comprising a multiple of '7, and bearing numbers designating year in century in various of said spaces, said numbers being arranged in radial columns in said spaces, the disc next to the rear disc being formed with window openings adapted to expose selected columns of num-- bers on the rear disc, said window openings being marked to designate a month for each portion of window opening corresponding to a radial space, said disc in front of the rear disc being marked with nesting spiral radially arranged sets of numbers designated day-in-month, the spiral starting point of each set being seven radial spaces away from the starting point of adjacent sets, the disc behind the front disc being formed with a window opening having an angular extent equivalent to one radial space and adapted to register with window openings with the disc in front of the rear disc, said disc behind the front disc being further formed with an arcuate window opening having a radial extent equivalent to 13 radial spaces and adapted to uncover day in month numbers in said sets, the front disc being formed with an arcuate Window opening having an angular extent being equivalent to seven radial spaces, and said window opening being positioned radially similarly to the first window opening in the disc behind the front disc, said front disc being formed with a second window opening having an angular extent similar to the angular extent of said first window opening in the front disc, and the radial position of said second window opening in the front disc being such as to expose seven columns of day-inmonth numbers in the disc in front of the rear disc, the rear disc having the greatest diameter, the disc in front of the rear disc having the next smaller diameter, the disc behind the front disc being still smaller in diameter, and the front disc being smallest in diameter, the disc in front of the rear disc being marked adjacent its periphery with monthly designations in alignment with the window openings therein, the portion of the front disc between the window openings therein being marked to indicate successively the days of the week from Sunday to Saturday.

MORRIS E. DO-NOW.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 662,954 Moeller Dec. 4, 1900 1,987,180 Chidester Jan. 8, 1935 2,134,183 Grantham Oct. 25, 1938 

